Meade Electric Focuser #1247

Telescope Warehouse (email link) provided a #1247 Electric Focuser for the ETX-125EC to me for evaluation. When it arrived it had French instructions instead of English. Since my French is rather rusty I contacted Meade and they mailed the English version to me. The single-sheet instructions were straightforward and I had no difficulty following them.

Warning: there is no caution in the instructions to tilt the OTA upwards to keep the focus shaft from falling inside the telescope. When removing the focus knob it is extremely important to keep the OTA pointed upwards.

I removed my Scopetronix FlexiFocus cable (which I really liked) and attached the large gear (see photo on the left).
I then attached the
motor housing to the rear of the ETX-125EC. I inserted a 9V battery into the focus handcontroller and connected the cable. The motor ran once for about a second. Thinking that maybe my battery was bad I replaced it. Nothing. I removed the motor housing and tried to run the motor without the "load" of the focus shaft. After several presses of the IN/OUT buttons I got the motor to run. Thinking that maybe the buttons just needed some "breaking in" and that all was well now, I re-attached the housing to the ETX. And again the motor would not run reliably. I removed the housing, checked the battery (it was good) and tried running the motor with no load. It would not run and then all of sudden it would start working but many times it would stop while holding down the same key. It would take several presses before it started to run again. The fast or slow speed setting didn't matter. I tried jiggling the cable and that didn't help. I was rather frustrated at this point.

A few days later I removed the focuser to pack it up and return it to Telescope Warehouse. On a whim I decided to check it and of course it ran just fine. So I reattached it to the ETX and it failed. I started to remove it again and as I loosened the mounting screw I tried to run it; worked! I couldn't find any position (loose or fully tightened) where I could duplicate a failure or a success. I decided that maybe my problems were over.

I took the ETX-125 outside, connected up my AC power adapter, and went through the Autostar alignments. I then viewed the Moon and tried out the focuser handcontroller. It was smooth in both speeds but VERY noisy. I changed to a 6.4mm eyepiece and again found the focusing OK. While working with the standard controller I had one Autostar automatic reset and one Proc Trap 2 error. I have never had either of these errors in several years of using the Autostar so I suspect that maybe some electrical interference from the focuser handcontroller. I switched to using the Autostar as the focuser controller (which provides four speeds instead of two). I had a lot of problems; the focuser gave out "tire squealing" sounds, would not start nor stop focusing reliably, and moved in jumps at times and smoothly at other times, regardless of the speed setting. Overall, I was not happy with the control that this focuser provided. Even though I like the convenience of my JMI electric focuser on my ETX-90RA, I decided to switch back to the FlexiFocus cable for the ETX-125EC. I returned the focuser to Telescope Warehouse.

Telescope Warehouse replaced the first focuser with a different one. This one worked smoothly without stalling and was somewhat quieter. I tried both the focuser handcontroller and the Autostar #497 with it. I was able to focus smoothly at all speeds with both controllers. I did notice that there appears to be some lag in focus movement, sometimes requiring an overshoot and an approach from the other direction. This wasn't too much an inconvenience, given the reduced vibration during focusing.

Several users of this model focuser have noted that the 9V battery in the focuser controller will run down quickly when the telescope is not in use. Unplugging the cable will likely avoid this problem.

And speaking of the cable, I wish it were longer. When plugged into the ETX AUX port and the telescope slews to the West, the cable is stretched around the telescope and could cause a problem as it wraps up. Using the focuser handcontroller avoids this problem as the cable plugs into the handcontroller. But then where do you put the handcontroller when not actively focusing? You would have to pick it up again to slew.

I did have one Autostar failure with the replacement focuser. I had just placed the Autostar back on the tripod leg (on a Velcro strip) and the Autostar display blanked and the drives stopped running. Nothing I did except powering off/on would revive the Autostar. Of course, cycling the power meant that I had to re-do the alignment.

Subsequent uses have not had any problems with the Autostar or focuser. It has worked like an electrical focuser should.

[01/08/04]

Subject: ETX-125 Electric Focuser problem and review.
Date: 1/7/04, 10:16
From: Mark (snm_0102@yahoo.com)
Just a quick description of a problem I had with my new 1247 electric
focuser which I bought for my ETX-125ec. Following the simple
instructions, I installed it fairly quickly. I sighted on a distant
street light and pushed the button to focus in. Nothing happened with
the focus, but the gears sounded like they where skipping and about to
strip. I was very unhappy. Instead of doing the smart thing and sending
it back for a replacement, I figured it was a simple system and I took a
look inside. I removed the three screws that held the two casing halves
together. The obvious problem was that the middle of three gears was
hardly contacting the drive gear on the motor. The motor and gears are
not adjustable, all internal parts are in molded holders. So I removed
the two gears and the motor. When I went to reinsert the motor, I
noticed that it wouldn't fit back in without a lot of force. It looked
like I was trying to fit a square block into a round hole. The part of
the motor that fits into it's molded socket has two flat sides (it is
not cylindrical). I turned the motor 90 degrees and tried again (making
sure the small wires were clear). It fit beautifully and seemed to be
properly aligned. I put the middle gear back on and it meshed perfectly.
After reassembly and installation, it worked like advertised. It did
make some strange noises, so I disassembled it again to put a little
lubricant on the middle gear shaft and the ends of the long gear
(originally there was no lubricant anywhere). Now it works wonderfully
and all I hear is the slight whir of the electric motor.
My review of this product is "I love it". But, it is about twice as
expensive as it should be, because it's pretty simple. The product is
well designed, but very poorly produced. I use it with my Autostar 497
controller and it can focus better than I can by hand. Even with my flex
cable, focusing was a hit and miss process. I'd have to try two or three
times to get it right on.
As always, this is the greatest ETX site.
Mark

[01/25/04]

Subject: Meade 1247 focuser review: buyer beware
Date: 1/24/04, 20:39
From: Sanjeev Joshi (sjoshi@gsb.uchicago.edu)
I am following up on a review a(1/8/2004) about the Meade 1247 focuser
from a gentleman named Mark. I had an identical problem with my
focuser, it stopped working after 3 hours. Gears kept slipping. I took
the risk, opened the unit, and tried to repair it. Unfortunately I was
less successful than the other gentleman and ended up with a broken one.
I have heard better reports about the JMI Motofocus, and have recently
ordered it. I will let you know how that work out.
Regards,
Sanjeev

[01/15/05]

Subject: ETX125 Electric Focuser
Sent: Wednesday, January 12, 2005 08:24:23
From: Phillips, Edward (Edward.B.Phillips@msfc.nasa.gov)
After playing around with my new ETX-125AT for a few months I decide to
add the Meade #1247 Electric Focuser to the scope.
I ordered it from ScopeTronics and received it in good condition and
ready to install. The unit did come with a small hand controller that
requires a 9v battery, but for my use I will be using the Autostar
control, so this included control is now in the excess equipment pile.
As a good consumer I did read the reviews that others had written on the
item and made me aware of the few items to check. First I just plug
the focuser into the scope and check it out running it forward and
reverse in different speeds and like the past reviews, it is not the
quietist item I have ever heard. So the next step, I took it apart and
check it out. I was simple to disassemble only held together by 3
Phillips head screws. The gears messed well, and looked of good
construction, but the blue grease, if you can call it grease, was in
globs here and there. The grease would just rotate on globs with the
gear. So taking some alcohol I clean the gears and plastic areas and
greased the gears and other pertinent areas. After reassembling the
focuser and running it to work the grease in I attached it to the scope
and waited for a clear night. I might note the focuser is little
quieter after greasing and assembled on the scope. After getting a
clear night I on January 9, 2005 I focused in on Saturn, shown in the
Meade LPI image I took, and all I have to say I love the focuser.

It is hands down better than the standard focus knob. I was able to
focus much quicker and better than with the standard knob. The only
draw backs I have to say the focuser replaces the manual focus knob
completely leaving you no option, but to use the electric focuser. It
would be nice to have a way to keep the manual option available and
maybe add another slower speed option on the focuser for micro
adjustments. All in all I am very happy with the Meade #1247 Electric
Focuser.
Edward B. Phillips
NASA Marshall Space Flight Center